Bag-in-box packaging of a variety of commodities is becoming increasingly more popular due to its economy, convenience and storage capabilities. The package, which is entirely disposable, consists of a flexible plastic bag for reception of the commodity in a sterile, air-free, noncontaminant environment, and a paperboard box for reception of the filled bag to facilitate safe transportion and handling of the same. The bag is equipped with a tubular spout through which the bag may be filled and the contents subsequently dispensed, and the box is provided with perforated tabs adjacent the location of the spout within the box to facilitate access to, removal of and mounting of the spout in a wall of the box near the bottom thereof for convenient gravity dispensing of the liquid contents. Examples of commodities economically packaged in this manner include milk, juice, and wine in one, three, five and ten gallon sizes, and even such viscous products as ketchup.
Manifestly, the spout must be equipped with a valve or spigot for controlling dispensing of the contents. A particularly successful form of spigot currently employed comprises an integral elastomeric member defining a diaphragmic transverse wall of deeply concave shape adapted to be inserted into the spout in sealing engagement with the outer end or lip of the spout and having finger manipulatable means on the wall for distorting a portion thereof from concave to convex configuration and disengaging said portion from the lip of the spout to permit dispensing of the contents, the wall snapping back into sealing position upon release of finger pressure. This spigot is shown and described in detail in U.S. Pat. No. 3,400,866 to L. A. Fattori, and an improved version in U.S. Pat. No. 3,443,728 to W. R. Scholle, the instant applicant.
As pointed out in the introductory portion of the Fattori patent, this spigot enjoys the advantages of being sufficiently low in cost for incorporation in a disposable container of the type above described; practical and efficient for shipping, storing and dispensing a wide variety of liquids including the special requirements for liquid food products, such as milk, juices and wine; operable at food refrigerating temperatures; neat and aesthetic in appearance; foolproof in operation; allowing optimum flow of liquid by exertion of finger pressure of one hand, leaving the other hand free for holding a receiving receptacle; providing rapid and automatic shut off upon release of the finger pressure; being free of drip or liquid hangup after shut off; and not leaking after passage of time or exposure to shock loading. In addition, because the spigot can be easily snapped onto and off of the spout, the spigot is compatible for filling containers through the delivery spout using high speed automatic machinery; closure of the container being effected after filling by snap-on engagement of the spigot which simultaneously loads the latter in prestressed shut off position.
However, the Fattori spigot suffers certain disadvantages in terms of its sealing effectiveness and pressure capacity. In particular, because the Fattori spigot effects its seal on the lip of the spout, it has little if any more than line contact with the spout at the seal and any nicks or deformities in the lip occurring during manufacture of the spout and/or the bag, shipping and handling of the empty bag and/or filling of the bag results in the spigot leaking and/or having very little resistance to internal pressure.
One effort to overcome some of these deficiencies of the Fattori spigot is shown in U.S. Pat. No. 3,972,452 to W. C. Welsh. As shown in this patent, the deeply concave wall of the Fattori spigot was further equipped with an axially inwardly extending cylindrical wall purportedly intended to gain additional bearing surface and sealing area on the interior surface of the spout. However, the attempt was marred by significant increase in the amount of material, and thus the cost, of the spigot and by increased difficulty in securing a wide open path for effective dispensing of the contents of the container.